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Flashcards in Bioenergetics Deck (60):
1

Physical activity

any movement produced by muscle contractions, which result in an elevated energy expenditure above the basal metabolic rate ex: work, sports, leisure activities, daily activities

2

Exercise

Structured physical activity executed on a regular basis with the objective to improve fitness and/ or performance

3

Bioenergetics

the science that involves studies of energetic events in the biological world is called bioenergetics

4

Thermodynamics

The physical science dealing with energy exchange is called thermodynamics

5

Laws of thermodynamics

1. Energy can neither be created nor destroyed 2. Whenever the energy is exchanged, the efficiency of the exchange will be imperfect and some energy will escape, usually in the form of heat

6

6 primary forms of energy

- thermal
- chemical
- mechanical
- electrical
- radiant
- atomic

7

3 ways energy is provided

Immediate (anaerobic galactic)
Non oxidative (anaerobic lactic)
Oxidative (aerobic)

8

General equation of bioenergetics

Echm (food)= Emch (work)+Ethrm (heat)

9

Metabolism oxidative equation

Food + O2--heat +co2+H2O

10

What is the upper limit of mechanical efficiency

25-30%

11

Mass

the amount of matter in a body measured in kg

12

Weight

is the force that results from the action of gravitation field on mass (N)

13

Unit for energy

Joule (J)

14

Unit for power

Watt (W)

15

What is 1 calorie in J

4.2 J

16

What is 1 kilocalorie in J

4.2 kJ

17

MET- metabolic equivalent

3.5 ml O2.kg-1.min-1

18

What is the energy equivalent of oxygen

the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius

19

Direct Calorimetry

Measurement of energy expenditure from body's heat production

20

Indirect Calorimetry

Measurement of energy expenditure from the ratio between VO2 and VCO2

21

Numerical value of the energy equivalent of oxygen

1 litre of O2= 5kcal

22

What is a MET

the ratio of the rate of energy expended during an activity to the rate of energy expended at rest.
1 met is equal to 3.5ml.kg-1.min-1

23

ECR (energy cost of running)

1kcal.kg-1.km-1

24

Monosaccharides

one sugar

25

Disaccharides

two sugars

26

Polysaccharides

multiple sugars

27

Lipids

contain C,H, O but less than carbohydrates, and sometimes contain P (phosphorus)

28

Main types of lipids

-Triglycerides or neutral fats
-phospholipids
-steroids
Eicosanoids

29

Triglycerides or neutral fats

-called fats when solid and old when liquids
-large molecules
-composed of three fatty acids bonded to glycerol molecule

30

Proteins

-compromise 10-30% of cell mass
-have most varied functions of any molecules

31

Amino acids

building blocks for protein

32

Enzymes

globular proteins that act as biological catalysts

33

What is ATP

chemical energy released when glucose is broken down is captured in ATP

34

What does ATP do?

directly powers chemical reactions in cells, offers immediate, table energy needed by body cells

35

Without ATP what happens?

Without ATP, molecules cannot be made or degraded, cells cannot shorten to tug on other structures, and life processes cease

36

What is ATP also known as

the common chemical intermediate

37

Respiration

conversion of the chemical energy in foodstuffs into useful chemical form

38

Cell work

Conversion of that useful form to other forms of energy

39

Metabolism

the su of processes occurring in a living organism

40

Metabolic rate

the rate of hear production, all cellular events result in heat

41

Anabolism

synthesis of large molecules from small ones (example: synthesis of proteins from amino acids)

42

Catabolism

Hydrolysis of complex structures to simpler ones (example: breakdown of proteins into amino acids)

43

what is it called when a substance loses electrons

oxidization

44

what is it called when a substance gains electrons

reduction

45

Complete glucose catabolism requires three pathways

1. Glycolysis
2. Krebs cycle
3. Electron transport chain and oxidative phosphorylation

46

Glycolysis

- also called glycolytic pathway
- involves 10-step pathway
- occurs in cytosol

47

Three major phases of glycolysis

Phase1. Sugar activation
Phase2. Sugar cleavage
Phase3. Sugar oxidation and ATP formation

48

Phase 1 sugar activation

phosphorylation activates glucose. Glucose is converted to fructose-1, 6- diphosphate

49

Phase 2 sugar cleavage

fructose -1 6-biphosphate is cleaved into two carbon fragments

50

Phase 3 Sugar oxidation and ATP formation

a. each 3-carbon fragment is oxidized by removal of a pair of H, which is picked up by NAD+
b. inorganic phosphate groups (Pi) are then attached to each oxidized fragment and 4 ATP molecules are formed

51

Citric acid cycle

occurs in mitochondria matrix and is fueled by pyruvic acid from glucose breakdown and fatty acids from fat breakdown

52

Main functions of the Krebs cycle

1. Carbon dioxide production 2. NADH and FADH production 3. produce some ATP (2 will be formed)

53

Electron transport chain phase 1

Phase 1 creates a proton (H+) gradient across mitochondrial membrane using high energy electrons removed from H from food fuels

54

Electron transport chain phase 2

Phase 2: chemiosmosis uses energy of the proton gradient to synthesize ATP

55

Redox

reduction oxidation reactions; represented by NADH/NAD

56

Glycogenesis

glycogen can be formed with excess glucose; catalyzed by glycogen synthase

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glycogenolysis

breakdown of glycogen via glycogen phosphorylase

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Lipogenesis

triglyceride synthesis that occurs when cellular ATP and glucose levels are high

59

Lipolysis

breakdown of stored fats into glycerol and fatty acids; reverse of lipogenesis

60

Nitrogen balance

homeostatic state where ratte of protein synthesis equals